Impact tests were performed on one-third size specimens of six low activation steels developed for structural applications in fusion reactors. Specimens were irradiated to ∼30 dpa at ∼375°C in the Fast Flux Test Reactor. Comparison of the results with those of control specimens and specimens irradiated to 10 dpa indicates that degradation in the impact behavior appears to have saturated by ∼10 dpa in at least four of these alloys. The most promising of the alloys, a 7.5Cr-2W alloy referred to as GA3X, exhibited the best impact properties, with no increase in ductile to brittle transition temperature or decrease in upper shelf energy between 10 and 30 dpa. Fractography supports the impact test results.